1. Technical Field
The invention relates to concealable brackets for supporting cantilevered overhangs of heavy counters or shelves.
2. Discussion of Art
In many kitchens, overhanging (cantilevered) countertops are desired to allow room for a person to sit with their knees under the countertop. Guidelines for installing granite countertops suggest that an overhang more than eight inches should have additional support to prevent the countertop from cracking and to prevent a cracked countertop causing bodily harm. In many cases, the support is desired to be invisible and unobtrusive so that a seated person, or a small child who chooses to walk or sit under the countertop, will not be injured by bumping into the support. It is also important that the support has sufficient contact with the overhang during installation and over the life of the kitchen to prevent the overhang cracking.
Current bracket designs consist of a material (usually wood or steel) that has a 90 deg angle and are mounted under the overhang. Brackets are either fastened to the visible surface of the wall or cabinet that supports the countertop overhang or consist of a flat piece of steel that is mounted to the top of cabinet. If a bracket is not firmly attached to the underside of the granite or the granite and/or cabinet shifts or deforms during use, it can still crack.
Exemplary conventional brackets include a two piece adjustable bracket, marketed by Brock International, as well as another two-piece adjustable bracket invented by Makainai (U.S. Pat. No. 5,076,648). However, these brackets protrude downward from the undersurface of a supported counter, into the knee- or head-space of a seated adult or a walking child. Thus, these conventional brackets fail to mitigate a known problem of potential bumps. Another known bracket is Tayar's track-mounted cantilever bracket (U.S. Pat. No. 5,695,163), which averts a risk of knee-bumps only by means of a highly visible track protruding from the wall.
FIG. 1 shows in cross-section a conventional standard bracket design 15 supporting an overhang 20 cantilevered from a wall 10. The typical bracket 15 is fabricated with a 90 degree angle and is mounted to a roomward surface of the wall 10 using several fasteners 30. The bracket 15 supports the weight of the overhang 20 with a compression strut 16, or alternatively the bracket may include a solid brace that fills the area 17 defined by the strut 16 (in which case, if made of wood, the bracket may be referred to as a “corbel”).
It is known that in order to properly support the weight of the overhang 20, the fasteners 30 need to be tightened and the strut 16 needs to be sufficiently sturdy such that the bracket 15 and overhang 20 are in contact with each other and extend together in parallel from the wall 10. However, the bracket 15 necessarily deflects under the load of the overhang, which cannot be ascertained at the time the bracket is manufactured. Therefore, in many installations shims may be required at the end of bracket 15 to ensure the overhang 20 remains horizontal, or the bracket 15 needs to be adjusted vertically along the wall 10 to ensure contact with overhang 20 by changing the fastener locations. This process of aligning the bracket to the wall and overhang can take several iterations. Although the conventional bracket 15 is functional, however all the mounting features are visible and the strut 16 and material 17 can be bumped into by small children or by a seated person's knee.